Apparatus for use in offshore operations



Dec. 26, 1961 R. P. KNAPP 3,014,347

APPARATUS FOR USE IN OFFSHORE OPERATIONS Original Filed Dec. 20, 1955 2Sheets-Sheet l 3 2 ll l3 l2 H l n I k:

FIG. 3.

INVENTOR. Richard P. Knupp,

R. P. KNAPP APPARATUS FOR USE IN OFFSHORE OPERATIONS Original Filed Dec.20, 1955 Dec. 26, 1961 2 Sheets-Sheet 2 INVENTOR. Richard P. Knapp,

United States Patent 3,014,347 APPARATUS FOR USE IN OFFSHORE OPERATIONSRichard P. Knapp, Houston, Tex., assignor, by mesne assignments, toJersey Production Research Company, Tulsa, Okla, a corporation ofDelaware Original application Dec. 20, 1955, Ser. No. 554,375, nowPatent No. 2,938,354, dated May 31, 1960. Divided and this applicationSept. 15, 1958, Ser. No. 760,936

3 Claims. (Cl. 61-465) Thepresent invention may be briefly described asa portable, stable structure suitable for use in offshore marineoperations which comprises a bottom bearing member having a plurality ofinterconnected vertically extending buoyancy columns connected to thebottom bearing member on their lower ends. A platform is supported bythe buoyancy columns on the upper ends of the buoyancy columns.Vertically adjustable auxiliary buoyancy means are arranged on all or aselected of the buoyancy columns with a portion of the buoyancy meansextending inboard of the structure and the remaining portion of thebuoyancy means extending outboard of the structure. The bottom bearingmember may be provided simply as a mat but may be constructed such thatit has buoyancy and may be suitably compartmented and provided with seachests, valves, and the like for flooding the compartments of the bottombearing member with water to ballast same and with suitable airconnections to blow the water from the compartments. Suitably thebuoyant bottom bearing member may have an open bottom and buoyancy giventhereto by maintaining a selected air pressure therein.

The structure of the present invention is provided with verticallyadjustable spuds arranged in the buoyant columns, such that they may beextended through the lower end of the buoyant columns to serve asmooring and anchoring means by positioning the spuds into the underlyingbottom of the marine location where the structure may be located. Thespuds-are'vertically adjustable such that they may be extended orretracted into the buoyant columns. The spuds may be extended orretracted by employing jacks of the hydraulic type and the like,suitable screw and wedge mechanisms, hydraulic means and-the like forraising andlowering the spuds. The spuds may suitably beprovided with ahydraulic lock, clamps or pins or other means for locking the spuds inposition as may be desired.

It is understood that the structure of the present invention maycomprise a plurality of extension supporting members constitutingbuilding blocks made up of interconnected, vertically extending columns.Thus, the platformmay be supported on a plurality of building blocks orextension supporting members connected to the bottom bearing members andwhen it is desirable to extend or lower the height of the structure foruse in deeper or shallower water the platform may be removed andbuilding blocks or extension supporting members either added to thestructure or subtracted therefrom. The extension supporting memberscomprising the interconnected, vertically extending columns would beconnected to each other, either by welding or by a bolted flangearrangement which would allow easy removal of ice the extensionsupporting members from or addition of the extension supporting membersto the structure.

It is contemplated that the auxiliary buoyancy means arranged on all ora selected of the buoyant columns may be removable therefrom. In short,the auxiliary buoyancy means may be provided with a slot and latcharrangement for placing same on the buoyant columns or the buoyancymeans may be provided with a removable segment for arranging same on thecolumns. Alternatively, the auxiliary buoyancy means may comprise aplurality of buoyant chambers interconnected and arranged aroundselected or all of the buoyant columns. The buoyancy means may alsocomprise a plurality of buoyant chambers arranged one upon another andseparable from each other such that buoyant chambers may be added toprovide additional buoyancy or buoyant chambers may be subtracted as maybe desired.

It is contemplated that the auxiliary buoyancy means may be inflatablesuch that when it is desired to provide auxiliary buoyancy the auxiliarybuoyancy means would be inflated and when the auxiliary bouyancy is nolonger required the buoyancy means maybe deflated as desired.

Thus, the present invention relates to a portable marine platform whcihprovides a stable foundation for machincry, drilling equipment, storagetanks, and the like, a base for salvage operation located over a body ofwater. The platform involving the structure may be moved with or withoutthe drilling equipment and the like from one Water location to anotheras desired or it may be converted to an improved type of permanentmarine structure. The platform is easily adjusted to permit safe use ina wide range of water depths.

The invention is particularly suitable to well drilling operations suchas oil and/ or gas or sulfur wells and may be used with an auxiliaryvessel or platform or suitably may be self-contained to provide thenecessary living quarters and warehouse facilities to conduct suchmarine operations.

The present invention will be further illustrated by reference to thedrawing in which:

FIG. 1 is a side elevation of the platform structure;

FIG. 2 is a horizontal section along line 2-2 of FIG. 1;

FIG. 3 is a vertical section along line 3--3 of FIG. 1;

FIG. 4 is a vertical section along line 4-4 of FIG. 1;

FIG. 5 is a plan view of the platform showing the working deck area andone arrangement of the buoyancy transport units;

FIG. 6 is a vertical section through the platform along line 6-6 of FIG.5;

FIG. 7 is a partial sectional view of an inflatable buoyancy transportunit and a transport column;

Referring now to the drawings in which identical numerals will beemployed to designate identical parts, and particularly to FIGS. 1 to 4,the structure comprises a working deck or platform structure generallyindicated by the numeral 11 which is of rectangular form and having agenerally flat working surface generally designated by the numeral 12.The working surface or platform 12 is suitably supported by longitudinalor transverse structural members 13 which are supported by a trussworkindicated generally by the numeral 14 composed of vertically extendingcolumns 15, diagonal members 16, and horizontal gint members 17. Thestructure is also provided with buoyant columns 18. The trusswork 14 andthe buoyant columns 18 terminate in a bottom bearing member 19 which isof general rectangular form with a suitable opening or openings 20 forthe conducting of drilling operations and the like. The bottom bearingmember is suitably constructed of longitudinal trating mooring spudsindicated generally by the numeral 10 which penetrate into the soilbelow the bottom bearing member 19 to provide resistance to lateralmovement, overturn, and vertical sinkage of the structure. The spuds 10are adjustable vertically and may be extended or retracted as may bedesired.

While the platform structure 12 is shown to have a square working deckand a square bottom bearing member with four buoyant columns forming thefour corners of a square horizontal section, it is possible to haveother configurations but it is preferred to have a square structurebecause it provides the most stable structure for a given structuralweight. It is to be understood, however, that other shapes andconfigurations may be used and may be preferable where structural weightis a secondary consideration. For example, a rectangular plan with thelength greater than the width may be more desirable where the width islimited by existing land facilities and a greater length is necessary toobtain the required working deck or bearing bottom member area.

As pointed out supra, it is'not necessary that the bottom bearing member19 be a watertight structure and it is preferable that the bottombearing member 19 have as little buoyancy as possible when the structureis in the moving position. For maximum stability during movingoperations the bottom bearing member should be completely flooded oropen to'the sea, with buoyancy limited to the volume of water displacedby the structural members. As pointed out before some water-tightcompartmen-ration may be desirable for the storage of liquid or to floatthe platform on the surface of the sea for delivery, overhaul and/ orrepairs.

Referring now to FIGS. 5 and 6 it is to be noted that the auxiliarybuoyancy means 37 are of general bag shape and extend both inboard andoutboard of the structure 11. The spuds 10 are shown driven into theunderlying land bottom 23 and with the auxiliary buoyancy means 37resting on the bottom bearing member 19 on bottom. In FIGS. 5 and 6 theauxiliary buoyancy means 37 are arranged permanently on the structure 11surrounding the columns 18. When the auxiliary buoyancy means 37 areemployed, it will be necessary to provide means for introducing airintoand removing air from the auxiliary buoyancy means 37. To this end aflexible connection such as 31 provided with a valve 32 may be arrangedto extend from the platform 12 to the buoyancy means 37. This flexibleconnection 31 may be a suitable hose which may be of deformable materialand reinforced with metallic members or may be a braided metal hose andthe like. The flexible member 31 may extend inboard and outboard of thestructure to provide air pressure to the members 37 or to relieve airpressure therefrom.

The auxiliary buoyancy means is shown in FIG. 7 in which an inflatablemember 37 is arranged on the columns 18 to surround same. The inflatablemember 37 extends both inboard and outboard of the structure and maysuitably be deflated and left to rest on the bottom bearing member 19when not in use and inflated when in use. To this end, a suitableflexible connecting member, such as 31, extending to the platform 12 andprovided with a valve 32 may be used for inflation and deflation asdesired.

In practicing the present invention with reference particularly to FIGS.5 and 6, the structure 11 would be floated into position "and theauxiliary buoyancy means 37 would then be flooded a su-fiicient amountof water to cause the structure to sink to the sea bottom 23 with themat 19 on bottom. Thereafter, the spuds 10 would be sunk or forced intothe earth 23 by suitable hydraulic means, not shown. Hydraulic pressureis then released which will allow some vertical movement of thestructure 11. The auxiliary buoyancy tanks 37 are then dewatered whichallow them to rise on the columns 1 8 to a floating position. Theauxiliary buoyancy means 37 are then latched or locked to the columns 18such that any force exerted by the tanks 37 will be exerted on thecolumns 18. The auxiliary buoyancy tanks 37 are then flooded with wateror has water pumped in to a level above sea level sufiicient to providea maximum preload on the bottom bearing member 19 in excess of thatwhich will be employed on the structure 11. As the auxiliary bags 37sink to the bottom 23, the soil. making up the bottom 23 is compactedunder the bottom bearing member 19 to cause moisture to be squeezed outtherefrom. The bags 37 are left on bottom to provide the maximum preloadfor the time indicated and then the spuds 10 are locked into positionagainst vertical movement. The bags 37 are then dewatered to a floatingposition, unlatched from the columns 18 and then removed therefrom asdesired.

The present invention is of considerable utility and advantage in that astable marine structure is provided which is easily removable and may beanchored permanently at a desired marine location. The structure hasstability in that the auxiliary buoyancy means extend both inboard andoutboard of the structure. Furthermore, the structure is adjustable inheight and may be moved from shallow to deep water or vice versa andused therein. Furthermore, the structure is of considerable utility inthat the auxiliary buoyancy means may be arranged permanently on thestructure or releasable therefrom.

The nature and objects of the present invention having been completelydescribed and illustrated, what I wish to claim as new and useful and tosecure by Letters Patent 1. Apparatus for providing stability to aportable structure suitable for use in oflshore marine operationscomprising a bottom bearing member, a plurality of interconnectedvertically extending columns connected to the bottom bearing member ontheir lower ends, and a platform supported by said columns on the upperends of said columns, which apparatus comprises vertically slidableinflatable auxiliary buoyancy means arranged embracedly on selected ofsaid columns, said buoyancy means being formed such that a portion ofsaid buoyancy means extends inboard of said portable structure and theremaining portion extends outboard of said portable structure when saidbuoyancy means is inflated, means maintaining said buoyancy means onsaid columns, and means for inflating and deflating said buoyancy means,said buoyancy means resting on said bottom bearing member when deflated.

2. Apparatus in accordance with claim '1 in which the inflation anddeflation means comprises a valved flexible connection member connectedto the auxiliary buoyancy means.

3. Apparatus in accordance with claim 2 in which the valved flexibleconnection means extends to the platform.

References Cited in the file of this patent UNITED STATES PATENTS2,423,832 Gearon July 15, 1947 2,534,480 Shannon Dec. 19, 1950 2,691,272Townsend et al. Oct. 12, 1952 2,900,794 Sutton Aug. 25, 1959

